1. Field of the Invention
This invention relates to a series of (heterocyclicthio)phenyl N-alkylcarbamates, (heterocyclicthio)phenyl N-acyl-N-alkylcarbamates and their thionocarbamate analogs. The said compounds have useful pesticidal properties, and in particular they are effective in destroying the adults and/or larvae of insects and other pests which tend to infest the skins of animals, especially those of sheep, cattle, horses, swine, and the like. They are therefore especially useful as ectoparasiticidal agents for treating such animals. They are also useful as insecticides for other applications.
As a result of the breeding of adult insects and other pests on animal skins, the larvae produced tend to burrow into the skins of the afflicted animals and thereby spoil the state of the skins, with the consequence, for example, that cattle hides and sheep skins and fleece, intended for the manufacture of leather, sheepskin and woolen goods, respectively, are reduced in quality. Furthermore, the state of health and the quality of the flesh of afflicted animals may be detrimentally affected. Certain insect larvae, for example the larvae of blowflies which tend to live in sheep skin, are capable of bringing premature death to the animal if present in sufficient abundance. Tick larvae, which tend to live in cattle hides, facilitate the transmission of diseases to afflicted animals to a marked degree.
It is therefore an object of the invention to provide a series of compounds having useful pesticidal properties, in particular against insects and other pests, such as blowflies, ticks and mites, which are the cause of ectoparasitic infections of animals, as well as against household or crop insect pests, e.g. houseflies.
2. Description of the Prior Art
A number of esters of carbamic acid are known to be useful pesticides, e.g. 2-isopropoxyphenyl N-methylcarbamate, 4-(dimethylaminophenyl)-3,5-dimethylphenyl N-methylcarbamate, 1-naphthyl N-methylcarbamate, 3-(1-ethylpropyl)phenyl N-methylcarbamate and 3-(1-methylbutyl)phenyl carbamate.
Belgian Pat. No. 659,636 discloses the use of 2-(4-chlorophenoxy)-4-chlorophenyl N-methylcarbamate and 2-(4-chlorophenoxy)-4,5-dichlorophenyl N-methylcarbamate as bacteriostats and inhibitors of pathogenic mycetes. Farmacia (Bucharest), 17, 721 (1969) describes a series of 4-(phenylsulfonyl)phenyl N-substituted-carbamates, wherein the substituent is methyl, ethyl, propyl, butyl, allyl or cyclohexyl. In Farmacia (Bucharest), 18, 27 (1970), there is described a series of 4-(4-tolylsulfonyl)phenyl N-substituted-carbamates, wherein the substituent is methyl, ethyl, propyl, butyl, allyl, C.sub.18 H.sub.37 or phenyl. N-acyl derivatives of aryl carbamates are described in British Pat. No. 982,235 as insecticides of reduced mammalian toxicity. West German Offenlegungsschrift No. 2,333,264 (and U.S. Pat. No. 3,884,962) disclose a variety of phenylthio-, phenylsulfinyl- and phenylsulfonyl-substituted phenyl carbamates and thionocarbamates, and N-acylated derivatives thereof.